What is System.map?

What is System.map?

Post by Victor Zand » Tue, 28 Jul 1998 04:00:00



Hi,

    I haven't been able to find any documentation that describes the
function and usage of the file System.map.  Where should I look?

    Every time I build a new kernel, I get a new System.map.  But this
file always has the same name, so if I want to boot more than one
kernel on the same filesystem, it appears that some kernel will have a
broken System.map.  Is that accurate?  If so, how do I configure the
kernel so that it has a distinct System.map file?

    Email replies appreciated.

Thanks,
Vic Zandy

 
 
 

What is System.map?

Post by Frank Sweetse » Tue, 28 Jul 1998 04:00:00



> Hi,

>     I haven't been able to find any documentation that describes the
> function and usage of the file System.map.  Where should I look?

>     Every time I build a new kernel, I get a new System.map.  But this
> file always has the same name, so if I want to boot more than one
> kernel on the same filesystem, it appears that some kernel will have a
> broken System.map.  Is that accurate?  If so, how do I configure the
> kernel so that it has a distinct System.map file?

the System.map files is used for resolving kernel addresses to their
symbolic names (functions, variables, etc).  the only time you'll really
need it is for debugging kernel oops data.  if you're not doing kernel
debugging, don't worry about it.

--
Frank Sweetser rasmusin at wpi.edu fsweetser at blee.net | PGP key available
paramount.res.wpi.net RedHat 5.1 kernel 2.1.111p1  i586  | at public servers
linux: because a PC is a terrible thing to waste


 
 
 

What is System.map?

Post by Blush Consultin » Wed, 29 Jul 1998 04:00:00


Sorry can't answer that but...
As well as that how do you upgrade /etc/module-info (is that it?) file, I
have still got module-info-2.0.30 but am using kernel 2.0.35. It still works
so it can't be that important but I have to wonder.

>Hi,

>    I haven't been able to find any documentation that describes the
>function and usage of the file System.map.  Where should I look?

>    Every time I build a new kernel, I get a new System.map.  But this
>file always has the same name, so if I want to boot more than one
>kernel on the same filesystem, it appears that some kernel will have a
>broken System.map.  Is that accurate?  If so, how do I configure the
>kernel so that it has a distinct System.map file?

>    Email replies appreciated.

>Thanks,
>Vic Zandy

 
 
 

What is System.map?

Post by Richard Blackston » Wed, 29 Jul 1998 04:00:00



> Hi,
>     I haven't been able to find any documentation that describes the
> function and usage of the file System.map.  Where should I look?
>     Every time I build a new kernel, I get a new System.map.  But this
> file always has the same name, so if I want to boot more than one
> kernel on the same filesystem, it appears that some kernel will have a
> broken System.map.  Is that accurate?  If so, how do I configure the
> kernel so that it has a distinct System.map file?

That depends how you implement your own system. One can use System.map
to feed klogd during bootup. Normal boot script files contain a line
like

     klogd -k /usr/src/linux/System.map

It is even more flexible if you have multiple kernel source trees
in your machine. For me, I usually prefer the version number so
that you can use something like

     KVERSION=`uname -r`
     klogd -k /usr/src/linux-$KVERSION/System.map

REB

 
 
 

What is System.map?

Post by Nelson Mina » Wed, 29 Jul 1998 04:00:00



> the System.map files is used for resolving kernel addresses to their
> symbolic names (functions, variables, etc).

Yep.

Quote:> the only time you'll really need it is for debugging kernel oops data.

Nope. It's also used by ps (and presumably other things in procps) to
resolve the WCHAN - this can be quite useful for debugging hung
processes with "ps -axl".

Unfortunately it doesn't always seem to work, even if you do have the
right System.map installed. Procps looks at /boot/System.map-2.x.yy,
then just plain ol /boot/System.map.

It's hard to remember to copy that file over after building a kernel.
It'd be nice if procps or someone checked that the file was correct.

 
 
 

What is System.map?

Post by Tomas Ogr » Thu, 30 Jul 1998 04:00:00




>> the System.map files is used for resolving kernel addresses to their
>> symbolic names (functions, variables, etc).

[snip some]
> It's hard to remember to copy that file over after building a kernel.

If you're using Debian, you can build the kernel with make-kpkg (from
the kernel-package*.deb), which turns the entire thing into a debian
package, putting all the files where they belong, saving the old kernel
as .old, running lilo if needed etc..

Does RH have anything similar?

/Tomas
--

|- Student of Computer Engineering at the University of Ume?
`- Sysadmin at ing.umu.se

 
 
 

What is System.map?

Post by Frank Sweetse » Thu, 30 Jul 1998 04:00:00



> If you're using Debian, you can build the kernel with make-kpkg (from
> the kernel-package*.deb), which turns the entire thing into a debian
> package, putting all the files where they belong, saving the old kernel
> as .old, running lilo if needed etc..

> Does RH have anything similar?

nope... have to see how hard it is to hack this together sometime this
weekend ;-)

--
Frank Sweetser rasmusin at wpi.edu fsweetser at blee.net | PGP key available
paramount.res.wpi.net RedHat 5.1 kernel 2.1.111p1  i586  | at public servers
"Use of unesessary * in the apprehension of the Blues Brothers
has been approved."

 
 
 

1. System.map not parseable as a System.map

After compiling and installing 2.2.14 with "bzlilo", I'm getting warning
messages such as:
Warning: /boot/System.map not parseable as a System.map
Warning: /usr/src/linux/System.map not parseable as a System.map
Warning: /System.map not parseable as a System.map            

After recompiling, I copied the "System.map" file in
/usr/src/linux-2.2.14 to the above three places, but am still getting
the warnings.

My lilo.conf is:
boot=/dev/hda
map=/System.map
install=/boot/boot.b
prompt
timeout=50
default=linux

image=/vmlinuz
        label=linux
        read-only
        root=/dev/hdb6

other=/dev/hda1
        label=dos

Any ideas?

--
Jack L. Owens             K6PWY



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